Field of the Invention
The present invention relates to an analysis of a pattern defect, an imprint apparatus, and an article manufacturing method.
Description of the Related Art
An imprint technique is coming into practical use as one lithography technique of manufacturing articles such as magnetic storage media and semiconductor devices. In an imprint apparatus, a pattern is formed by bringing a mold into contact with an imprint material on a substrate. A pattern defect may be caused at this time, and a reduction in this defect is a task.
One factor in causing the pattern defect is that bubbles are trapped between the mold and the imprint material on the substrate when a pattern portion of the mold and the imprint material are brought into contact with each other. If the imprint material is cured while the bubbles remain, a defect may be caused in the formed pattern due to insufficient filling.
Another factor in causing the pattern defect is that foreign particles (foreign substances) adhere to a pattern surface. If the particles adhere to the pattern surface, the pattern formed on the substrate is distorted, causing a transfer defect.
There are a plurality of causes of the pattern defect as described above, and thus different measures need to be taken for the respective causes of the defects. Japanese Patent Laid-Open No. 2010-225693 describes a technique of determining a defect due to insufficient filling if a defect size is large and correcting the arrangement amount of imprint materials. In addition, Japanese Patent Laid-Open No. 2013-539204 describes a technique of taking measures to grasp the periodicity and total number of defect data by an FFT analysis, and clean a substrate if the total number exceeds a reference.
In the technique of Japanese Patent Laid-Open No. 2010-225693, however, there are many determination errors because the size of a defect region is used as grounds for determining the defect due to insufficient filling, and thus the effect of reducing the defect is small. In the technique of Japanese Patent Laid-Open No. 2013-539204, the measures are not taken by classifying defects for the respective causes, and thus the effect of reducing the defect is also small.